J'ai enfin trouvé la solution :
If you get an error like the one below
"error: unrecognized db option: "db3" ignored."
You will need to reinstall rpm as it looks like rpm is damaged.
The rpm package only comes in .rpm format so will need to use the
rpm2cpio command to install. rpm2cpio can be copied from another machine
if you dont have it.
mkdir -p /var/tmp/xxx
cd /var/tmp/xxx
rpm2cpio rpm-4.0.3-1.03.6x.*.rpm | cpio -dim
chmod -R 755 *
tar cf - ./usr ./etc | (cd /; tar xvf -)
Then do "rpm --rebuilddb" to fix your database.
:-D
